<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>
<body>


<div id="app">
    <div v-if="count==3">div1</div>
    <div v-else-if="count==4">div2</div>
    <div v-else>div3</div>
    <hr>
    <div v-show="count==3">div v-show</div>
    <br>


    <input v-model="count">

</div>

<script src="js/vue.js"></script>

<script>
    //1.创建vue的核心对象
    new Vue({
        el:"#app",
        data(){
            return {
                username:"",
                url:"https://www.baidu.com",
                count:3
            }
        },
        methods:{
            show(){
                alert("我被点了......")
            }
        }
    })





</script>
</body>
</html>